The conventional manufacturing method of a diving mask, which is connecting the lens with materials such as plastics (silicone etc.) when in moulding, then connect to a main frame and skirt (as shown in FIG. 1), has at least the following disadvantages:
1. The lens is damageable when removing or exchanging the lens having for different sighted degrees (such as nearsighted, farsighted, presbyopic . . . ) or because it is difficult to reassemble, as a result a leaking phenomenon occurs at the edge of the lens.
2. The plastic is closely connected with the lens because the lens (or glass) is directly placed into the die cavity during injection. The thickness of glass due to tolerance is not easily controlled in a certain range, and because there are some problems relating to heat-expanding and cold-contracting during injection, which causes undesired breaking and a latent danger for the eyes of a user.